This invention relates to a power tilt, power steering device for an outboard drive and more particularly to an improved hydraulically assisted device for outboard drives.
It is well known that many forms of outboard drives employ hydraulic cylinders powered by an electric motor driven hydraulic pump for achieving tilt and trim operation. Recently, it has also been proposed to employ the same hydraulic source to provide a power assist for the steering. These types of hydraulic assists are particularly popular in connection with large displacement outboard drives such as large displacement outboard motors.
With such an arrangement, in order for the hydraulic assist to be available it is necessary to for the electric motor to be started and drive the hydraulic pump so as to generate sufficient hydraulic force for operation of the hydraulic motor. This can cause delays in the operation and also can result in high consumption of electrical energy.
It has been proposed to employ a system wherein an accumulator is charged by the hydraulic pump and this accumulator pressure is employed for the hydraulic assist. Although this type of device offers one solution to the problem, it is not necessarily the best one.
For example, when a hydraulic accumulator is required, it is necessary to provide additional hydraulic lines to and from the accumulator and the power assist devices. In addition, it is necessary to cycle the electric motor to insure that the accumulator is charged to adequate pressure and these systems generally operate on higher pressure than conventional systems.
It is, therefore, a principle object to this invention to provide an improved power assist system for an outboard drive.
It is a further object to this invention to provide a hydraulic assist mechanism for an outboard drive wherein there will be no delay in the availability of hydraulic fluid under pressure, but the use of accumulators and complicated circuitry are avoided.
It is a further object to this invention to provide an improved power assisted, tilt/trim and steering arrangement for a marine outboard drive.